I disagree with the time to buy a house. The best time to buy is during the winter. The only advantage to waiting until spring/summer is that's when there are many more houses on the market, so you might be able to find a nicer house.
BUT, if a house doesn't sell, it will drag into the winter, and the seller will get more desperate to take your offer because they know if it didn't sell during the peak season, it's not likely to sell during the off-season, and they'll have to drop the asking price the next spring anyway. In the meantime, they are stuck in the house still paying for it.
All realtors will tell you to put your house on the market in the spring, and that your best chance to sell is during the spring/summer.